On Bi-R-Diagonal Pairs of Operators
arXiv:1902.01041
Abstract
We study the properties of the analogue of R-diagonal operators in the setting of bi-free probability. Products of bi-R-diagonal pairs of operators that are -bi-free are studied and powers of such pairs are found to also be bi-R-diagonal. It is moreover shown that the joint -distribution of a bi-R-diagonal pair of operators remains invariant under the multiplication by a -bi-free bi-Haar unitary pair and equivalent characterizations of bi-R-diagonal pairs are developed.
40 pages. v2: Major revisions. Paper significantly reorganized and expanded. New combinatorial framework introduced to streamline arguments, many proofs rewritten with added diagrams and several new results included (notably on distinct powers and independence of bi-R-diagonal pairs)